zwiftout/src/stats/normalizedIntensity.ts

36 lines
1.1 KiB
TypeScript

import { pipe, sum } from "ramda";
import { Interval } from "../ast";
import { average } from "./average";
import { intervalsToIntensities } from "./intervalsToIntensities";
// Starting at the beginning of the data, calculate 30-second rolling average
const windowSize = 30;
const rollingAverages = (intensities: number[]): number[] => {
if (intensities.length < windowSize) {
throw new Error(`Workout must be at least ${windowSize} seconds long`);
}
const averages: number[] = [];
let rollingSum: number = sum(intensities.slice(0, windowSize));
averages.push(rollingSum / windowSize);
for (let i = 0; i < intensities.length - windowSize; i++) {
rollingSum -= intensities[i];
rollingSum += intensities[i + windowSize];
averages.push(rollingSum / windowSize);
}
return averages;
};
const fourthPower = (x: number) => Math.pow(x, 4);
const fourthRoot = (x: number) => Math.pow(x, 1 / 4);
export const normalizedIntensity = (intervals: Interval[]): number => {
return pipe(
intervalsToIntensities,
rollingAverages,
(averages) => averages.map(fourthPower),
average,
fourthRoot,
)(intervals);
};